For consumers who have previously coloured their hair, the colour and condition of the hair is not homogenous along the entire length. The hair strands will comprise root virgin hair or new growth hair which has not been previously coloured and conversely at the tips hair which has experienced one or multiple hair colouring treatments. The tips of the hair are typically the most damaged portions of the hair and are characterised by an overly deposition of dyes or over-bleaching due to previous oxidative or non-oxidative hair colorations. The intermediate hair length is typically a medium between these two extreme conditions. The problem with current retail hair colour products, e.g. hair colour products comprising direct dyes is that they do not take into account the differences of properties between the different portions of the hair. It is rather challenging even for experienced home colour users to control the dye deposition provided by a retail hair colour product comprising direct dyes in order to not overly deposit direct dyes on hair lengths and tips since the instructions provided in hair colour retail kits are typically imprecise, often not followed and the results achieved are not comparable with those from a salon stylist. The overall colour appearance is typically not as homogeneous as that provided by a salon stylist.
Therefore, there is a need to provide a simple method as well as a simple retail kit for colouring hair with hair colouring compositions comprising direct dyes which gives the user the possibility of obtaining a different hair colour effect on different portions of the hair, for example a different colour effect on hair roots vs. hair lengths and tips to provide a smooth root-to-tip transition on hair which has been previously coloured.